Roller twisting apparatus

ABSTRACT

Strand twisting apparatus comprising a pair of rollers arranged to form a nip between them and roller drive means to rotate the rollers so as to feed a strand through the nip and to reciprocate the rollers in opposite phase transversely of the strand feed direction. One of said rollers is mounted in a yoke pivotally mounted on the machine frame for movement toward and away from the other roller and biasing means is provided to bias said one roller toward said other roller with a predetermined biasing force.

United States Patent H 1 in] 3,714,771

Henshaw et al. 45 F b, 6, 1973 I ROLLER TWISTING APPARATUS 3,377,792 4/1968 Walls et a1. "37777.1 x

[75] Inventors: David Ernest Henshaw, Werner Emil Otto Knothe, Lionel Stern, all 'v Emmmerlohn Fawkes of Victoria, Australia Att0rneySughrue, Rothwell, Mlon, Zlnn & Macpeak [73] Assignee: Commonwealth Scientific and Industrial Research Organization, [57] ABSTRACT Campbell, Australia I 7 i i r 7 Strand twlstlrlg apparatus comprlslng a palr of rollers Flledl 7 1971 arranged to form a nip between them and roller drive [21] Appl. No.: 114,014 means to rotate the rollers so as to feed a strand through the nip and to reciprocate the rollers in op- 52 us. Cl 57/77 42 Posite Phase transversely the Strand feed direction- 51 Int. Cl. ..D01 h 2 l502g 170s one Said mum is mounted in a Yoke Pivmany 58 Field of Search ..57/34-45, 51, 51.6 "mumed the machine frame for movement Ward 57/774 7742 and away from the other roller and biasing means is provided to bias said one roller toward said other 56] References Cited roller with a predetermined biasing force.

UNITED STATES PATENTS 10 Claims, 4 Drawing Figures 2,601,394 6/1952 Hansen ..57/77.4 X

PATENIED FEB s 1975 SHEET 10F 2 m-Wm: 4.1%

PATENTED FEB 6 I975 sum 2 or 2 ROLLER TWISTING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to reciprocating roller twisting apparatus of the general type disclosed in our Australian Pat. No. 288,664, i.e. apparatus comprising a pair of oppositely rotated and transversely reciprocated nip rollers.

2. Description of Prior Art One of the principal practical problems which has been encountered in the operation of the particular forms of apparatus described in Patent No. 288,664 is that the spacing between the twisting rollers must be accurately controlled if the best results are to be obtained. The present invention provides apparatus of the same general type but in which the need for gap adjustment by the operator is eliminated.

SUMMARY According to the invention there is provided strand twisting apparatus comprising a pair of rollers arranged to form' a nip between them and roller drive means to rotate the rollers so as to feed a strand through the nip and to reciprocate the rollers in opposite phase transversely of the strand feed direction wherein one of said rollers is mounted on the machine frame and the other is mounted in a pivotable assembly pivotally mounted on the frame for movement towards and away from the said one roller and the said other roller is biased towards said one roller with a predetermined biasing force.

Preferably said other roller is dosposed above said one roller and preferably counterbalanced. Means is provided to oppose the moment about the pivot axis due to the weight of the roller and its mounting.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention may be more fully explained one embodiment thereof will now be described with reference to the accompanying drawings, in which:

FIGS. 1 and 2 are contiguous at the line X-X and together forma partly sectioned schematic side elevation of an apparatus constructed in accordance with the invention;

FIG. 3 is a partly sectioned end elevation of the apparatus showing a roller biasing spring 27; and

FIG. 4 shows an alternative form of roller biasing means. A

DESCRIPTION-OF THE PREFERRED EMBODIMENT The apparatus of FIGS. 1 to 3 comprises upper and lower hollow rollers 1,2 which form a nip 3. Lower roller 2 is mounted on two air bearings 4 formed at the ends of a pair of mandrels 6 which are mounted on a nected at its outer end to a rotating and reciprocating drive (not shown). The inner end of connecting rod 8 is attached to a mounting piece 9 which is in turn attached to the interior of the roller. The connection between the connecting rod and the connecting piece is by means of a rubber bush 11 which absorbs vibration and compensates for any misalignment between the axis of the connecting rod and the axis of the roller.

Roller 1 is mounted by means of air bearings ona pair of mandrels 12 carried by a yoke frame 13 which is pivotally mounted on a pair of pivot pegs 14A, 15A which extend from ends of a pair of pins 14, 15 clamped to frame 7. The air bearings supporting the roller 1 on mandrels 12 are similar to those supporting the lower roller 2, being supplied with air through manifolds in the respective mandrels, and they are not detailed in the drawings. Pins-14, 15 are held within clamping sockets in frame 7 and the end pegs 14A, 15A project into ball races 16 fitted into bores 17 formed in yoke frame 13. Peg 14A is eccentric to the pin 14 whereas peg 15A is concentric with the pin 15. The eccentricity of peg 14A enablesroller l to be adjusted relative. to roller 2 by angular adjustment of pin 14 such that the vertical spacing between the roller axes is constant throughout the lengths of the rollers. Pin 15 is given a 20 lb. axial preload to minimize fretting corrosion in ball races 16. Roller 1 is connected to a rotating and reciprocating drive by means of connecting rod (not shown) which is similar to that for roller 2. The two drive mechanisms are powered by a common electric drive motor. The motor has two speeds a fast speed for normal running of the apparatus and a low speed for inching during threading operations.

At one end of the apparatus, a counter-weight 18 is fastened to yoke frame 13 by means of a bent stud 19 which extends through an opening 20 in frame 13 and is fitted with a pair of adjustment nuts 21. By appropriate repositioning of nuts 21 on stud 19, the moment of the counter-weight about the axis of pivot pegs 14A, 15A can be adjusted. A-locating dowel 22 on frame 13. is able to slide within an opening 23 in the counter-weight during this adjustment. The pivoted assembly of weight 18, frame 13 and roller 1 is damped by a dashpot comprised of chamber 24 which is formed in frame 7 and is charged with a viscous damping medium and a plunger 26 which is fastened to the counterweight and projects into the damping medium. The

damping medium can be a silicone oil of suitable' viscosity.

In use of the apparatus, counter-weight 18 is adjusted so that the upper roller assembly is completely balanced about pivot pins 14, 15 and the upper roller is biased toward the lower roller by meansv of a spring 27 connected between pegs 28, 29 fixed to yoke frame 13 and the main frame 7 respectively. The biasing force applied by spring 27 is quite small. More particularly the spring biasing force may be in the range 4 to 30 ounces. With such a light loading, there is an effective gap between the rollers during operation and, because of the counter-weight balancing, this gap is independent of vibration of the machine in the vertical direction. Additionally, the dashpot eliminates high frequency gap variation' but allows the top roller position to drift so as tomaintain a constant loading.

In the illustrated apparatus, the twisting efficiency is controlled by the loading of the top roller toward the bottom roller. Too high a load will lead to the occurrence of hot spots on the rollers with consequent abrasion of the rubber but it has been found that with a loading of less than 30 ounces the short and long term stability of the amount of twist inserted by the rollers is remarkably constant. At the same time the need for gap adjustment by the operator has been eliminated.

FIG. 4 shows alternative means 30.for loading the topjroller 1 toward the bottom roller 2. This alternative form of loading means is designed so that the loading of the top roller can be relieved to provide a predetermined lower biasing force. It is particularly beneficial in cases where the rollers are normally driven at a high speed but can be inched at low speed during threading operations following end breaks and during doffing. It has been found that the twisting efficiency of the rollers increases with decreasing speed of operation so that the twist levels imparted during inching operations will be much higher than those imparted during high speed running if the loading of the top roller remains unchanged. By relieving the loading on the roller during inching operations reasonably regular twist level can be maintained.

The alternative roller loading means 30 comprises a I weighted rod 31 which is suspended from a peg 28A fixed to yoke frame 13. Rod 31 has a pair of upwardly facing abutments 32, 33 and carries a pair of weights 34, 35. weight 34 rests on abutment 32 and weight 35 rests on abutment 33 when a solenoid 36 is energized to pull a spring-loaded lifting yoke 37 downwardly against the influence of its loading spring 38. During normal of example only and many modifications are possible.

For example, means could be provided to enable the tension in spring 27 to be adjusted. Such means could comprise a plate cam rotatably mounted on frame 7 in place of pin 29 and engaging a cam follower attached to the lower end of the spring. The cam follower'could comprise a slotted vertical bar provided with a pair of vertically spaced follower rollers engaging opposite sides of the cam such that the follower can can be moved positively upwards and downwards, the cam shaft slidably engaging the slot to act as a guide and to keep the rollers in alignment with the center of the cam. Alternative cam or screw devices could also prove satisfactory. Instead of providing a counter-weight, the

' weight of the top roller assembly could be supported on tension springs and the required loading of the top roller toward the bottom roller could be applied by resting weights on it. Furthermore such an arrangement could be designed without the pivots, the vertical movement of the roller being constrained by guides. The pivot system-is preferred since, once set, it"ensures parallelism of the roller'axes.

It is accordingly to be understood that the invention is in no way limited to the specific constructional details described herein but includes many modifications and variations within the scope of the appended claims.

lclaim:

1. Strand twisting apparatus of the typev comprising a pair of contra-rotating rollers arranged to form a nip between them and to reciprocate in opposite phase said apparatus comprising:

a frame,

means supporting one of said rollers on said frame,

a pivotable assembly comprising a yoke supporting the other of said rollers,

pivot means pivotally supporting said pivotable assembly on said frame about a pivot axis displaced from and parallel to the axis of rotation of said one roller and biasing means to apply a biasing force to said pivotable assembly having a movement about said pivot axis such as to bias said other roller towards said one roller with a predetermined biasing force.

2. Strand twisting apparatus as claimed in claim 1,

wherein said pivot means comprises a pair of pivot pegs carried by the frame to define the pivot axis and wherein one of the pivot pegs is adjustable transversely relative to the other to enable the spacing between the roller axes to be made substantially constant throughout the lengths of the rollers.

3. Strand twisting apparatus as claimed in claim 2, wherein said one pivot peg extends eccentrically from an end of a pin clamped to the frame so as to be rotatably adjustable.

4. Strand twisting apparatus as claimed in claim 1, wherein counterbalancing means is provided to oppose the moment about the pivot axis due to said biasing force and to the weight of said pivotable assembly.

5. Strand twisting apparatus as claimed in claim 1, wherein there is a damping means to damp swinging movement of said pivotable assembly about said pivot axis.

6. Strand twisting apparatuses claimed in claim 1, wherein the biasing means is conditionable to relieve the bias of said other roller toward said one roller toja predetermined lower biasing force.

7. Strand twisting apparatus as claimed in claim 1, wherein said rollers are driven by electrically powered drive means operable at two differing speeds, the biasing means is conditionable to relieve the bias of said other roller by electrically responsive means and the latter means is electrically connected with the drive means so that the said other roller is .biased with the predetermined'force when the drive means is operated at the higher of the two speeds and with the lower biasing force when the drive means is operated at the lower of the two speeds.

8. Strand twisting apparatus as claimed in claim 1, wherein the biasing means comprises a weight support member hung from said pivotable assembly, a weight normally supported by the weight support member so as to contribute to the biasing force, and relief means operable to lift and support the weight whereby to relieve the bias of said other roller toward the one roller to a predetermined lower biasing force.

biasing force, and counterbalance means to provide a moment about said pivot axis opposite to said biasing force. 10. Strand twisting apparatus as claimed in claim 9, wherein said rollers are operable at two differing speeds and biasing means is provided whereby a different biasing force is imposed on said pivotable assembly depending on the speed of operation of the rollers.

. UNITED STATES PATENT OFFICE CETIFICATE OF CDRECTION Patent No. 3, 714, 771 Dated F ebruary 6, 1973 Inventor(x) David E rnestI-Ikenshaw, Werner Emil Otto Knothe and Lionel Stern It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

The Priority Date was omitted. Should read:

--Austra1ia February 9, 1970 ...PA 2 /70.

Signed and sealed this 20th day of? November 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Officer Acting Commissioner of Patents F ORM PO'-1 050 (10-69) USCOMM-DC 60376-P69 w u.S. GOVERNMENT PRINTING OFFICE Iss9 o-qes-au. 

1. Strand twisting apparatus of the type comprising a pair of contra-rotating rollers arranged to form a nip between them and to reciprocate in opposite phase said apparatus comprising: a frame, means supporting one of said rollers on said frame, a pivotable assembly comprising a yoke supporting the other of said rollers, pivot means pivotally supporting said pivotable assembly on said frame about a pivot axis displaced from and parallel to the axis of rotation of said one roller and biasing means to apply a biasing force to said pivotable assembly having a movement about said pivot axis such as to bias said other roller towards said one roller with a predetermined biasing force.
 1. Strand twisting apparatus of the type comprising a pair of contra-rotating rollers arranged to form a nip between them and to reciprocate in opposite phase said apparatus comprising: a frame, means supporting one of said rollers on said frame, a pivotable assembly comprising a yoke supporting the other of said rollers, pivot means pivotally supporting said pivotable assembly on said frame about a pivot axis displaced from and parallel to the axis of rotation of said one roller and biasing means to apply a biasing force to said pivotable assembly having a movement about said pivot axis such as to bias said other roller towards said one roller with a predetermined biasing force.
 2. Strand twisting apparatus as claimed in claim 1, wherein said pivot means comprises a pair of pivot pegs carried by the frame to define the pivot axis and wherein one of the pivot pegs is adjustable trAnsversely relative to the other to enable the spacing between the roller axes to be made substantially constant throughout the lengths of the rollers.
 3. Strand twisting apparatus as claimed in claim 2, wherein said one pivot peg extends eccentrically from an end of a pin clamped to the frame so as to be rotatably adjustable.
 4. Strand twisting apparatus as claimed in claim 1, wherein counterbalancing means is provided to oppose the moment about the pivot axis due to said biasing force and to the weight of said pivotable assembly.
 5. Strand twisting apparatus as claimed in claim 1, wherein there is a damping means to damp swinging movement of said pivotable assembly about said pivot axis.
 6. Strand twisting apparatus as claimed in claim 1, wherein the biasing means is conditionable to relieve the bias of said other roller toward said one roller to a predetermined lower biasing force.
 7. Strand twisting apparatus as claimed in claim 1, wherein said rollers are driven by electrically powered drive means operable at two differing speeds, the biasing means is conditionable to relieve the bias of said other roller by electrically responsive means and the latter means is electrically connected with the drive means so that the said other roller is biased with the predetermined force when the drive means is operated at the higher of the two speeds and with the lower biasing force when the drive means is operated at the lower of the two speeds.
 8. Strand twisting apparatus as claimed in claim 1, wherein the biasing means comprises a weight support member hung from said pivotable assembly, a weight normally supported by the weight support member so as to contribute to the biasing force, and relief means operable to lift and support the weight whereby to relieve the bias of said other roller toward the one roller to a predetermined lower biasing force.
 9. Strand twisting apparatus of the type comprising a pair of driven contra-rotating oppositely reciprocating rollers arranged to form a nip between them said apparatus comprising: a frame, means supporting one of said rollers on said frame, a pivotable assembly including said other roller mounted on said frame about a pivot axis parallel to the axis of rotation of said one roller and biased about said pivot axis so as to bias said other roller towards the said one roller with a predetermined biasing force, and counterbalance means to provide a moment about said pivot axis opposite to said biasing force. 